diff --git a/src/main/java/net/openhft/chronicle/hash/serialization/impl/InstanceCreatingMarshaller.java b/src/main/java/net/openhft/chronicle/hash/serialization/impl/InstanceCreatingMarshaller.java
index d2f22eb88..ed02fcb18 100644
--- a/src/main/java/net/openhft/chronicle/hash/serialization/impl/InstanceCreatingMarshaller.java
+++ b/src/main/java/net/openhft/chronicle/hash/serialization/impl/InstanceCreatingMarshaller.java
@@ -21,6 +21,7 @@ import net.openhft.chronicle.hash.serialization.DataAccess;
 import net.openhft.chronicle.hash.serialization.SizedReader;
 import net.openhft.chronicle.map.ChronicleMapBuilder;
 
+import java.io.Serializable;
 import java.lang.reflect.Constructor;
 
 /**
@@ -29,7 +30,7 @@ import java.lang.reflect.Constructor;
  *
  * @param <T> the type of objects deserialized
  */
-public abstract class InstanceCreatingMarshaller<T> {
+public abstract class InstanceCreatingMarshaller<T> implements Serializable {
 
     /**
      * The class of objects deserialized.
diff --git a/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java b/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
index 60e4d5201..2611b5c0a 100755
--- a/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
+++ b/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
@@ -36,8 +36,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.*;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.util.*;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -47,7 +45,8 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import static java.lang.Double.isNaN;
 import static java.lang.Math.round;
 import static net.openhft.chronicle.bytes.NativeBytesStore.lazyNativeBytesStoreWithFixedCapacity;
-import static net.openhft.chronicle.core.Maths.*;
+import static net.openhft.chronicle.core.Maths.isPowerOf2;
+import static net.openhft.chronicle.core.Maths.nextPower2;
 import static net.openhft.chronicle.hash.impl.CompactOffHeapLinearHashTable.*;
 import static net.openhft.chronicle.hash.impl.util.Objects.builderEquals;
 import static net.openhft.chronicle.map.DefaultSpi.mapEntryOperations;
@@ -118,9 +117,6 @@ public final class ChronicleMapBuilder<K, V> implements
 
     private static final double UNDEFINED_DOUBLE_CONFIG = Double.NaN;
 
-    private static final int XML_SERIALIZATION = 1;
-    private static final int BINARY_SERIALIZATION = 2;
-
     private static boolean isDefined(double config) {
         return !isNaN(config);
     }
@@ -1369,18 +1365,10 @@ public final class ChronicleMapBuilder<K, V> implements
                 try (FileInputStream fis = new FileInputStream(file);
                      ObjectInputStream ois = new ObjectInputStream(fis)) {
                     Object m;
-                    byte serialization = ois.readByte();
-                    if (serialization == XML_SERIALIZATION) {
-                        m = deserializeHeaderViaXStream(ois);
-                    } else if (serialization == BINARY_SERIALIZATION) {
-                        try {
-                            m = ois.readObject();
-                        } catch (ClassNotFoundException e) {
-                            throw new AssertionError(e);
-                        }
-                    } else {
-                        throw new IOException("Unknown map header serialization type: " +
-                                serialization);
+                    try {
+                        m = ois.readObject();
+                    } catch (ClassNotFoundException e) {
+                        throw new AssertionError(e);
                     }
                     @SuppressWarnings("unchecked")
                     VanillaChronicleMap<K, V, ?> map = (VanillaChronicleMap<K, V, ?>) m;
@@ -1421,10 +1409,7 @@ public final class ChronicleMapBuilder<K, V> implements
 
         try (FileOutputStream fos = new FileOutputStream(file);
              ObjectOutputStream oos = new ObjectOutputStream(fos)) {
-            if (!trySerializeHeaderViaXStream(map, oos)) {
-                oos.writeByte(BINARY_SERIALIZATION);
-                oos.writeObject(map);
-            }
+            oos.writeObject(map);
             oos.flush();
             map.initBeforeMapping(fos.getChannel());
             map.createMappedStoreAndSegments(file);
@@ -1450,43 +1435,6 @@ public final class ChronicleMapBuilder<K, V> implements
         }
     }
 
-    private static <K, V> boolean trySerializeHeaderViaXStream(
-            VanillaChronicleMap<K, V, ?> map, ObjectOutputStream oos)
-            throws IOException {
-        Class<?> xStreamClass;
-        try {
-            xStreamClass =
-                    Class.forName("net.openhft.xstream.MapHeaderSerializationXStream");
-        } catch (ClassNotFoundException | NoClassDefFoundError e) {
-            xStreamClass = null;
-        }
-        if (xStreamClass == null) {
-            LOG.info("xStream not found, use binary ChronicleMap header serialization");
-            return false;
-        }
-        try {
-            oos.writeByte(XML_SERIALIZATION);
-            Method toXML = xStreamClass.getMethod("toXML", Object.class, OutputStream.class);
-            toXML.invoke(xStreamClass.newInstance(), map, oos);
-            return true;
-        } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException |
-                InstantiationException e) {
-            throw new AssertionError(e);
-        }
-    }
-
-    private static Object deserializeHeaderViaXStream(ObjectInputStream ois) {
-        try {
-            Class<?> xStreamClass =
-                    Class.forName("net.openhft.xstream.MapHeaderSerializationXStream");
-            Method fromXML = xStreamClass.getMethod("fromXML", InputStream.class);
-            return fromXML.invoke(xStreamClass.newInstance(), ois);
-        } catch (ClassNotFoundException | NoSuchMethodException | InvocationTargetException |
-                IllegalAccessException | InstantiationException e) {
-            throw new AssertionError(e);
-        }
-    }
-
     ChronicleMap<K, V> createWithoutFile(
             SingleChronicleHashReplication singleHashReplication, ReplicationChannel channel) {
         replicated = singleHashReplication != null || channel != null;
diff --git a/src/main/java/net/openhft/xstream/MapHeaderSerializationXStream.java b/src/main/java/net/openhft/xstream/MapHeaderSerializationXStream.java
deleted file mode 100644
index 1df6db36c..000000000
--- a/src/main/java/net/openhft/xstream/MapHeaderSerializationXStream.java
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- *      Copyright (C) 2015  higherfrequencytrading.com
- *
- *      This program is free software: you can redistribute it and/or modify
- *      it under the terms of the GNU Lesser General Public License as published by
- *      the Free Software Foundation, either version 3 of the License.
- *
- *      This program is distributed in the hope that it will be useful,
- *      but WITHOUT ANY WARRANTY; without even the implied warranty of
- *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *      GNU Lesser General Public License for more details.
- *
- *      You should have received a copy of the GNU Lesser General Public License
- *      along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-package net.openhft.xstream;
-
-import com.thoughtworks.xstream.XStream;
-import com.thoughtworks.xstream.converters.reflection.SunLimitedUnsafeReflectionProvider;
-
-public class MapHeaderSerializationXStream extends XStream {
-
-    public MapHeaderSerializationXStream() {
-        super(new SunLimitedUnsafeReflectionProvider());
-    }
-}